With the aim of effecting bonding, reinforcement or replenishment of the same or different materials, various sealing materials are used in the assembly process of architecture, automobiles and the like, and various materials having different curinging modes and principal chains have been proposed depending on each purpose. However, a material having all required characteristics including (1) high weather resistance, (2) high heat resistance, (3) quick hardenability, (4) low moisture permeability and (5) adhesiveness with inorganic materials cannot be found in commonly used sealing materials for double glazing use, and virtually nothing is known about a material in which (6) one-pack stability is taken into consideration.
For example, silicone based sealing materials of addition type curing mode satisfy the above characteristics (1), (2), (3), (5) and, in some cases, (6) but do not have the characteristic (4), so that environmental problems such as peripheral pollution are observed when they are used as sealants. Also, a high polymer material having a saturated hydrocarbon polymer as its principal chain, which has been disclosed in JP-A-1-198673 (the term "JP-A" as used herein refers to a "published unexamined Japanese patent application"), cannot satisfy the aforementioned characteristic (3) because of its condensing type curing mode.
On the other hand, double glazing produced by binding two or more layers of glass plates is used in order to improve adiabatic property, sound insulation property and the like of glass. In the double glazing, air between the glass plates is shielded from the outside to form a dead air space. In order to form such a dead air space, a sealant is used as occasion demands in the peripheral area between the glass plates via a spacing member.
Examples of the characteristics required for the sealant to be used in the production of double glazing include
a) to maintain adhesion between two glass plates, or between a metal or the like spacing member for keeping a space between two glass plates and the two glass plate, stably for a prolonged period of time, PA1 b) to prevent permeation and invasion of moisture into the dry air sealed in the dead air space and the like. PA1 (A) a hydrocarbon polymer of 500 to 300,000 in molecular weight having at least one alkenyl group in one molecule, PA1 (B) a curing agent having at least two hydrosilyl groups in one molecule, PA1 (C) a hydrosilylation catalyst, and PA1 (D) a tackifier. PA1 such as (Pt)e(ViMe.sub.2 SiOSiMe.sub.2 Vi)e and Pt[(MeViSiO).sub.4 ]f; PA1 such as Pt(PPh.sub.3).sub.4 and Pt(PBu.sub.3).sub.4 ; PA1 such as Pt[P(OPh).sub.3 ].sub.4 and Pt[P(OBu).sub.3 ].sub.4 ; and PA1 such as bisacetylacetonatoplatinum [Pt(AcCH.sub.2 Ac).sub.2 ] and bisethylacetoacetatoplatinum [Pt(AcCH.sub.2 COOEt).sub.2 ]
However, a sealant which can satisfy both of these characteristics a) and b) is not known in the conventionally used sealants, so that two types of sealants having respective characteristics must be used in combination. For example, characteristics required as so-called double seal are given by the use of a silicone or thiokol based sealant as a material having the characteristic of a) and a butyl based hot melt sealant as a material having the characteristic of b). However, when the butyl based hot melt sealant having the characteristic of b) is used alone, thoroughly satisfactory results cannot be obtained in terms of weather resistant adhesiveness and mechanical characteristics so that there is caused a problem that the characteristic of a) cannot be satisfied.
In view of the above-described situations, it is therefore an object of the present invention to provide a curable composition and a sealant for double glazing use which have the aforementioned characteristics (1) to (6) and excellent mechanical property.
That is, the present invention is to provide a composition for double glazing use which satisfies the aforementioned characteristics a) and b) and also has quick hardenability by addition type curing, can be produced by a line process and is able to be used as a one-pack type sealant having excellent shelf stability and mechanical properties.